1. Field of the Invention
The present invention relates to a method for dehalogenation treatment of a halogen-containing flame-retardant resin composition and relates to a method for preventing harmful substances such as dioxins generated at the time of burning resin compositions and promoting reuse of the resin.
2. Related Art of the Invention
In order to provide flame-retardability for resin such as epoxy resin, phenol resin, polystyrene resin and the like to be used for domestic electric appliances such as a television and appliances relevant to information such as a display, a personal computer and the like, a halogen-containing flame-retardant of such as decabromodiphenyl ether is added or a halogen is introduced into the resin skeleton. The halogen-containing flame-retardant evolves an active halogen when being heated so as to cover the surface of the resin composition and shut oxygen to provide a fire-retarding effect.
However, it has been well known that harmful halogenated dibenzodioxins and halogenated dibenzofurans are emitted when a halogen-containing flame-retardant resin composition is incinerated in a common refuse treatment apparatus.
Hence, regarding an unnecessary halogen-containing flame-retardant resin composition, techniques of detoxification have been developed. As disclosed in Japanese Patent Application Laid-Open No. 2000-117738, it is common to thermally decompose resin and remove and recover it in the forms of halogenated low molecular weight compounds and treatment is generally carried out at a high temperature, at 300° C. or higher. Also, as disclosed in Japanese Patent Application Laid-Open No. 2000-44966, the resin is hydrogenated and decomposed in the presence of a catalyst to remove and recover it in the forms of halogenated low molecular weight compounds. The treatment temperature is also high, 300 to 420° C., as in the case of the thermal decomposition. However, in these cases, since the resin is thermally decomposed or hydrogenated and decomposed, although an oil or a gas can be recovered to be reused, it cannot be reused as resin. Besides that, dioxins are probably produced by heating at the time of the treatment.
As described above, regarding a halogen-containing flame-retardant resin composition, no technique relevant to methods for promoting reuse of resin while detoxicating the halogen has been disclosed.